1. Field of the Invention
This invention relates generally to heat transfer, and, more particularly, to cooling assemblies and methods to remove at least some of the heat produced by a heat source, such as an electronic component.
2. Description of Related Art
Electronic components such as integrated circuits or semiconductor chips, hereafter referred to as xe2x80x9cchipsxe2x80x9d, are well known and commonly used in the art to perform electronic functions. When in use, the chips often produce significant levels of heat. To reduce the heat generated, the chip size needs to be decreased, which causes the heat to be concentrated into a smaller area. As technology has increased the capacity of the chips to perform functions, it has been found that the amount of concentrated heat produced has increased significantly. The increased level of heat produced by these chips can lead to a number of problems, for example, elevated levels of heat can potentially cause the chip to malfunction.
Various methods have been employed in the art to dissipate heat from chips. One method involves creating a forced airflow across the chip using a fan or blower. Another method involves mounting a heatsink on the surface of the chip. Heatsinks are typically manufactured from a metal having a high thermal conductivity, such as aluminum, and are mounted onto the surface of the chip to dissipate the heat produced by means of thermal conduction. Heatsinks typically comprise a plurality of parallel fins that are mounted on a base and which serve to facilitate the radiation and convection of the conducted heat by providing an increased surface area. Often a fan or blower will be used to provide a forced airflow across the heatsink fins to increase their heat transfer capacity.
The two most significant modes of heat transfer are heat conduction and heat convection. Heat conduction is the transfer of heat through a solid medium. Heat conduction can be through a single solid medium or can be from one solid medium to another adjacent solid medium. The transfer of heat is based on a temperature differential, i.e. heat flowing from a hot body to a cold body, until temperature equilibrium between the bodies is reached. Heat convection is the transfer of heat away from a hot solid medium to a cooler body of air. The air, typically ambient, has a generally constant temperature. Heat is convected away by air currents generated by the warming of the air near the hot solid medium, and/or by a forced flow of air past the hot solid medium. Both conduction and convection are useful in providing heat dissipation from electrical devices.
The network of heat transfer pathways through which heat flows determines the overall heat transfer characteristics and is a significant factor in the ability to adequately dissipate the generated heat. The subject area of heat generation and dissipation within a system is sometimes referred to as the thermal management of the electronic system. The heat is conducted away from the chip and through the various thermal pathways to reach an outer surface of the heatsink. The heat can then be convected away from the outer surface to the adjacent air mass.
As new semiconductor designs are becoming smaller and are capable of increased processing capacity, the amount of concentrated heat generated has increased dramatically. To compound the problem, high performance integrated circuit chips are often mounted in close proximity to other heat generating chips on a printed circuit board, and frequently the circuit board is itself disposed within a confined area of an electronic device. Chips located in close proximity to each other will act as secondary heat sources on each other by radiant heat transfer, thereby increasing the amount of heat dissipation needed, while at the same time elevating the air temperature surrounding the chips, which acts to restrict the rate of total heat transfer. The commonly used methods of cooling that are mentioned above have sometimes been found to be inadequate for cooling high performance electronic systems.
Another area of concern in heatsink design is airflow. As the package sizes for electronic systems get smaller, the more difficult it becomes to provide and direct an adequate airflow to the various heat sources and through the system. The problem of effective temperature control has become a major industry concern and resulted in an increased focus on thermal management within the electronic systems.
There exists a need for improved cooling system designs that can effectively dissipate heat away from semiconductor chips, integrated circuits and other related electronic components.
One embodiment of the present invention is a cooling system comprising a housing and at least one divider disposed within the housing. The at least one divider creates a plurality of airflow channels through the housing.
Another embodiment of the invention is a method for dissipating heat from heat sources within an electrical assembly comprising at least partially separating the heat sources with a divider. Separate airflow channels are created, whereby the separated heat sources are disposed within the separated airflow channels. Forced airflow streams are generated through the separated airflow channels, thereby dissipating heat from the heat sources into the forced airflow streams.